Yesterday's Technology at Today's Prices
#47
Token Toyota Mod
iTrader: (50)
Join Date: Jun 2004
Location: Palo Alto, CA
Posts: 52,306
Car Info: Something german
Originally Posted by sperry
Hey dude... want a UniChip?
All you need is a MBC (I got one of theose just lying around too), an up-pipe, TBE and you should be good to go w/ my crappy engine management!
Serously, I'd sell the MBC (it's a nice TurboXS screw-adjustable one) and the UniChip/EFi/Harness for like $100.
...assuming you can run an MBC on your car. I hear rumors that '04+ cars straight up can't use 'em.... Aaron?
All you need is a MBC (I got one of theose just lying around too), an up-pipe, TBE and you should be good to go w/ my crappy engine management!
Serously, I'd sell the MBC (it's a nice TurboXS screw-adjustable one) and the UniChip/EFi/Harness for like $100.
...assuming you can run an MBC on your car. I hear rumors that '04+ cars straight up can't use 'em.... Aaron?
#49
Warm Fuzzy Admin
iTrader: (45)
Join Date: Mar 2001
Location: Sacramento, CA
Posts: 13,799
Car Info: 97 LOB, 05 FXT, 03 Tundra
IIRC, open-loop delay = really, really bad partial throttle, full boost if the ECU isn't managing stuff. It doesn't start dumping fuel (open-loop) soon enough to prevent issues if you're running more boost than stock, since the closed maps assume you're running at a certain boost level when you're actually higher.
EPA voodoo to keep from dumping fuel into the motor when its not necessary.
Partial throttle, full boost = slagged pistons
EPA voodoo to keep from dumping fuel into the motor when its not necessary.
Partial throttle, full boost = slagged pistons
#50
VIP Member
iTrader: (1)
Join Date: Dec 2002
Location: Reno, NV
Posts: 842
Car Info: '94 SVX, '02 WRX
Originally Posted by Aaron@S-S
IIRC, open-loop delay = really, really bad partial throttle, full boost if the ECU isn't managing stuff. It doesn't start dumping fuel (open-loop) soon enough to prevent issues if you're running more boost than stock, since the closed maps assume you're running at a certain boost level when you're actually higher.
EPA voodoo to keep from dumping fuel into the motor when its not necessary.
Partial throttle, full boost = slagged pistons
EPA voodoo to keep from dumping fuel into the motor when its not necessary.
Partial throttle, full boost = slagged pistons
I can see how that's bad.
#51
Warm Fuzzy Admin
iTrader: (45)
Join Date: Mar 2001
Location: Sacramento, CA
Posts: 13,799
Car Info: 97 LOB, 05 FXT, 03 Tundra
Originally Posted by sperry
So basically, there's a delay between close to open loop switching that can mean the car is at full boost in closed-loop for longer than the simple parial throttle conditions we were seeing on the 02-03 WRXs?
I can see how that's bad.
I can see how that's bad.
Yeah, like 1-2 seconds. Injectors go from <60% duty cycle at full throttle at high RPM to ~90%, but only after a significant delay; EGT's shoot up to almost 1700 degrees, AFR's are like 14.5+
Bad stuff. I guess more accurately would be partial fueling, full boost, but that's basically throttle anyways.
They're trying to minimize open-loop conditions. A reflash from a good tuner ()will eliminate the issue, because the closed-loop maps are more accurate, and open-loop parameters are adjusted.
#52
VIP Member
iTrader: (1)
Join Date: Dec 2002
Location: Reno, NV
Posts: 842
Car Info: '94 SVX, '02 WRX
Originally Posted by Aaron@S-S
Yeah, like 1-2 seconds. Injectors go from <60% duty cycle at full throttle at high RPM to ~90%, but only after a significant delay; EGT's shoot up to almost 1700 degrees, AFR's are like 14.5+
Bad stuff. I guess more accurately would be partial fueling, full boost, but that's basically throttle anyways.
They're trying to minimize open-loop conditions. A reflash from a good tuner ()will eliminate the issue, because the closed-loop maps are more accurate, and open-loop parameters are adjusted.
Bad stuff. I guess more accurately would be partial fueling, full boost, but that's basically throttle anyways.
They're trying to minimize open-loop conditions. A reflash from a good tuner ()will eliminate the issue, because the closed-loop maps are more accurate, and open-loop parameters are adjusted.
#53
Warm Fuzzy Admin
iTrader: (45)
Join Date: Mar 2001
Location: Sacramento, CA
Posts: 13,799
Car Info: 97 LOB, 05 FXT, 03 Tundra
Originally Posted by sperry
Is that just an attempt to get better mileage results? Or is that a side effect of going to the fly-by-wire throttle?
#54
VIP Member
iTrader: (1)
Join Date: Dec 2002
Location: Reno, NV
Posts: 842
Car Info: '94 SVX, '02 WRX
Originally Posted by Aaron@S-S
More about mileage, as the DBW doesn't add more than .25ms tot he response time; it's enough that you notice it going from a DBW to a cable-driven car, but not on the same scope we're talking here.
#55
Warm Fuzzy Admin
iTrader: (45)
Join Date: Mar 2001
Location: Sacramento, CA
Posts: 13,799
Car Info: 97 LOB, 05 FXT, 03 Tundra
Originally Posted by sperry
I thought it might be an issue w/ the DBW programming in the ECU, not so much a delay due to the computer actuating the throttle.
#57
the artist formerly known as mcdrama
iTrader: (23)
Join Date: Apr 2004
Location: Santa Cruz Mountains, CA.
Posts: 6,428
Car Info: WRBP 2015 WRX Premium/CVT
bump this, I want more info on this. Where did this open/closed loop information source from? I have seen a lot of posts on forums about this, but after googling, I can not find a reliable source of the bad side effects of this open/closed loop.
I just have a catless uppipe in my 04 wrx wagon and after 12K miles I am getting CELs P0544/P0546. I am thinking of getting EcuTek tuned after learning about this, assuming its true. =x
I just have a catless uppipe in my 04 wrx wagon and after 12K miles I am getting CELs P0544/P0546. I am thinking of getting EcuTek tuned after learning about this, assuming its true. =x
#59
the artist formerly known as mcdrama
iTrader: (23)
Join Date: Apr 2004
Location: Santa Cruz Mountains, CA.
Posts: 6,428
Car Info: WRBP 2015 WRX Premium/CVT
Originally Posted by RussB
there's a sticky in the 2.0l forum over on nabisco all about it. engine management will fix the problem.